Linear polarized passive monopole antenna for receive and transmit applications with 10 mm element fixture for telescopic or biconical elements.   

Specifications:

Application

The vertical passive monopole antenna VPMP 9242 is equipped with a 10 mm element fixture to accept several different element types, e.g. telescopic, biconical or collapsible conical elements. In order to improve the efficiency, especially at frequencies below 25 MHz the VPMP 9242 comes with a broadband toroid transformer. Since monopoles are always unsymmetrical antennas in contrast to dipoles, braid currents are existing on the coaxial feed cable. The influence of the braid currents can be minimized using a ground plane as large as possible, acting as rf-counterpoise on the one hand and suppressing the braid currents (at least at high frequencies) on the other hand. Generally, the use of a ground plane will improve reproducibility. If the coaxial feed cable of VPMP is touch-sensitive, this indicates the presence of braid currents. The following steps help to reduce the influence of unwanted braid currents: Connect the flange of VPMP with your amplifier using a short, wide, and low-inductance metal strip. Use a ground plane as large as possible.  Use a coaxial feed cable that is loaded with appropriate ferrites to suppress the unwanted currents.  

  Options:

Opt. GP: Aluminium groundplane 0.6 x 0.6 m

Selection of Rods available: FBAB 9177, FBAL 9178, BBA 9106, BBAL 9136